The Cloudflare API is pretty handy for updating DNS clients, so I wrote a little wrapper around fetching all my known hosts, and updating the external IP for each of them.

This script is based on the List and Fetch APIs:

• List DNS Record
• Update DNS Records

Feel free to fork or contribute.

You will need:

1. An API Key

• Go to the Overview page for your domain in Cloudflare, and to get Get your API Token.
• You can create a new API Token, make sure it has DNS.Read and DNS.Edit permissions for All zones in Zone Resources.

2. The Zone ID for the Zone you want to update
   • Go to the Overview page for your domain in Cloudflare, and you should see a section for API. You can find the Zone ID there.

Create a JSON file called config.json with the following contents:

{
  "API_KEY": "<my api key>",
  "ZONE_ID": "<my zone id>"
}

Now, you can run:

# Easiest: If you have Node.js and npx installed:
npx cloudflare-update-dns -c /path/to/my/config.json

# Or: If you have Node.js and want to install as a bin:
npm i cloudflare-update-dns -g # This will make "cloudflare-update-dns" available system-wide.
cloudflare-update-dns -c /path/to/my/config.json

The command will output:

$ cloudflare-update-dns
Loading config.json...
Successfully loaded config.json!
Fetching records...
Finished fetching 4 record(s).
Updating records...
Attempting to update record "myamazingwebsite.net"...
Successfully updated record "myamazingwebsite.net"!
Attempting to update record "stuff.myamazingwebsite.net"...
Successfully updated record "stuff.myamazingwebsite.net"!
Attempting to update record "things.myamazingwebsite.net"...
Successfully updated record "things.myamazingwebsite.net"!
Attempting to update record "www.myamazingwebsite.net"...
Successfully updated record "www.myamazingwebsite.net"!
All records updated

If you want to run a cronjob that runs the script at intervals:

# Every 5 minutes (change to whatever frequency you prefer).
*/5  * * * * cloudflare-update-dns >> /var/log/cloudflare-update-dns/update.log

Create a JSON file called config.json with the following contents:

{
  "API_KEY": "<my api key>",
  "ZONE_ID": "<my zone id>"
}

And put in the root of this application:

/
  buid/
  src/
  ...
  config.json <-- Here
  ...
  package-lock.json
  package.json
  ...

Now, you can run npm run build && ./bin/cloudflare-update-dns.js -c config.json from the app root.

This script uses the API token, and does not require the email and/or password combination. Typically, when you create a new API token, it will give you a sample curl request. Compare the token used in that script with the one you use in the configuration for this script.